The present invention relates generally to closure devices having slider members movably installed upon interlocking fastening strips and, more particularly, to a method and apparatus for assembling slider members onto such fastening.strips. The invention may be employed in traditional fastener areas and is particularly well suited for use in assembling closure devices for flexible storage containers, such as plastic bags.
The use of closure devices for fastening storage containers, including plastic bags, is generally well known. Furthermore, the manufacture of closure devices made of plastic materials is generally well known to those skilled in the art, as demonstrated by the numerous patents in this area.
A particularly well-known use for closure devices is in connection with flexible storage containers, such as plastic bags. Such closure devices provide a convenient way to close the bag in order to retain matter therein.
Conventional closure devices typically utilize mating fastening strips or closure elements which are used to selectively seal the bag. With such closure devices, however, it is often difficult to determine whether the fastening strips are fully occluded. This problem is particularly acute when the fastening strips are relatively narrow. Accordingly, when such fastening strips are employed, there exists a reasonable likelihood that the closure device is at least partially open.
Such fastening strips are particularly difficult to manipulate or handle by individuals with limited manual dexterity. Thus, in order to assist these individuals and for ease of use by individuals with normal dexterity, the prior art has provided sliders for use in opening and closing the fastening strips, as disclosed, for example, in U.S. Pat. Nos. 4,199,845, 5,007,142, 5,007,143, 5,010,627, 5,020,194, 5,070,583, 5,283,932, 5,301,394, 5,426,830, 5,431,760, 5,442,838, and 5,448,808. Some of these sliders include a separator finger which extends at least partially between the fastening strips. When the slider is moved in the appropriate direction, the separator finger divides the fastening strips and opens the bag.
While the use of a slider certainly facilitates the opening and closing of interlocking fastening strips, there are certain difficulties involved with installing and assembling the slider onto the fastening strips and with retaining the slider thereon. In an attempt to rectify some of these difficulties, the prior art has provided a variety of slider designs including various single-piece sliders, as disclosed, for example, in U.S. Pat. Nos. 5,010,627, 5,067,208, 5,070,583, and 5,448,808. Such slider members, however, suffer from assorted deficiencies including, for example, a relatively complex construction, a high relative cost, and a design which lends itself to difficult assembly onto the interlocking fastening strips.
Accordingly, a general object of the present invention is to provide a method of assembling slider members onto interlocking fastening strips which overcomes deficiencies in the prior art.
A more specific object of the present invention is to provide a method of conveniently assembling slider members onto interlocking fastening strips.
A related object of the present invention is to provide a slider member which facilitates convenient assembly onto interlocking fastening strips.
A further object of the present invention is to provide a method as characterized above which operates in a simple and economical manner.
An additional object of the present invention is to provide a method as characterized above which lends itself to reliable operation and use.
In accordance with these and other objects, several embodiments of slider members and methods of assembling such slider members onto interlocking fastening strips are disclosed herein. The slider member comprises a pair of spaced-apart side walls and an intermediate body portion therebetween. In addition, each side wall includes an interior surface with an inwardly projecting shoulder formed thereon, an exterior surface, and opposed end surfaces which interconnect the interior and exterior surfaces. The method of assembling such slider members onto interlocking fastening strips comprises the steps of: engaging respective side walls of a slider member with first and second tools; moving the first tool away from the second tool to resiliently spread apart the side walls of the slider member; inserting interlocking fastening strips between the spread apart side walls of the slider member; and releasing the first and second tools from engagement with the side walls of the slider member to permit the side walls to resiliently return to a relaxed position wherein the shoulders formed on the interior surfaces of the side walls are positioned to obstruct removal of the slider member from the interlocking fastening strips.